perf(renderer): reduce sidebar task list render work

src/renderer/components/sidebar/GlobalTaskList.tsx

@@ -223,7 +223,48 @@ interface GlobalTaskRowProps {
   ownerColorName?: string | null;
 }
 
-const GlobalTaskRow = memo(function GlobalTaskRow({
+function taskCommentsDisplayEqual(
+  prev: GlobalTask['comments'],
+  next: GlobalTask['comments']
+): boolean {
+  if (prev === next) return true;
+  if (!prev || !next) return (prev?.length ?? 0) === (next?.length ?? 0);
+  if (prev.length !== next.length) return false;
+  for (let i = 0; i < prev.length; i += 1) {
+    if (prev[i].id !== next[i].id || prev[i].createdAt !== next[i].createdAt) {
+      return false;
+    }
+  }
+  return true;
+}
+
+function taskSidebarFieldsEqual(prev: GlobalTask, next: GlobalTask): boolean {
+  return (
+    prev === next ||
+    (prev.id === next.id &&
+      prev.teamName === next.teamName &&
+      prev.teamDisplayName === next.teamDisplayName &&
+      prev.teamDeleted === next.teamDeleted &&
+      prev.subject === next.subject &&
+      prev.owner === next.owner &&
+      prev.status === next.status &&
+      prev.createdAt === next.createdAt &&
+      prev.updatedAt === next.updatedAt &&
+      prev.projectPath === next.projectPath &&
+      prev.reviewState === next.reviewState &&
+      prev.kanbanColumn === next.kanbanColumn &&
+      prev.deletedAt === next.deletedAt &&
+      taskCommentsDisplayEqual(prev.comments, next.comments))
+  );
+}
+
+function effectiveRenamingKey(task: GlobalTask, renamingKey: string | null): string | null {
+  const taskRenamingKey = `${task.teamName}:${task.id}`;
+  return renamingKey === taskRenamingKey ? renamingKey : null;
+}
+
+const GlobalTaskRow = memo(
+  function GlobalTaskRow({
     task,
     isPinned,
     isArchived,
@@ -242,7 +283,7 @@ const GlobalTaskRow = memo(function GlobalTaskRow({
     onRenameCancel,
     getDisplaySubject,
     ownerColorName,
-}: GlobalTaskRowProps): React.JSX.Element {
+  }: GlobalTaskRowProps): React.JSX.Element {
     const taskRenamingKey = `${task.teamName}:${task.id}`;
     const effectiveRenamingKey = renamingKey === taskRenamingKey ? renamingKey : null;
 
@@ -293,7 +334,28 @@ const GlobalTaskRow = memo(function GlobalTaskRow({
         </AnimatedHeightReveal>
       </TaskContextMenu>
     );
-});
+  },
+  (prev, next) =>
+    taskSidebarFieldsEqual(prev.task, next.task) &&
+    prev.isPinned === next.isPinned &&
+    prev.isArchived === next.isArchived &&
+    prev.isNew === next.isNew &&
+    prev.teamOffline === next.teamOffline &&
+    effectiveRenamingKey(prev.task, prev.renamingKey) ===
+      effectiveRenamingKey(next.task, next.renamingKey) &&
+    prev.hideTeamName === next.hideTeamName &&
+    prev.hideProjectName === next.hideProjectName &&
+    prev.showTeamName === next.showTeamName &&
+    prev.onTogglePin === next.onTogglePin &&
+    prev.onToggleArchive === next.onToggleArchive &&
+    prev.onMarkUnread === next.onMarkUnread &&
+    prev.onRename === next.onRename &&
+    prev.onDelete === next.onDelete &&
+    prev.onRenameComplete === next.onRenameComplete &&
+    prev.onRenameCancel === next.onRenameCancel &&
+    prev.getDisplaySubject === next.getDisplaySubject &&
+    prev.ownerColorName === next.ownerColorName
+);
 
 interface TaskRowsProps {
   tasks: GlobalTask[];

src/renderer/components/sidebar/TaskFiltersPopover.tsx

@@ -53,7 +53,7 @@ export const TaskFiltersPopover = ({
   }, [open, filters]);
 
   const allSelected =
-    STATUS_OPTIONS.length > 0 && STATUS_OPTIONS.every((opt) => draft.statusIds.has(opt.id));
+    open && STATUS_OPTIONS.length > 0 && STATUS_OPTIONS.every((opt) => draft.statusIds.has(opt.id));
 
   const handleSelectAll = (): void => {
     if (allSelected) {
@@ -89,6 +89,7 @@ export const TaskFiltersPopover = ({
           <Filter className="size-3.5" />
         </button>
       </PopoverTrigger>
+      {open ? (
         <PopoverContent className="w-64 p-3" align="end" sideOffset={6}>
           <div className="space-y-3">
             <div>
@@ -206,6 +207,7 @@ export const TaskFiltersPopover = ({
             </Button>
           </div>
         </PopoverContent>
+      ) : null}
     </Popover>
   );
 };

test/renderer/components/sidebar/GlobalTaskList.test.ts

@@ -35,6 +35,7 @@ interface StoreState {
 
 const storeState = {} as StoreState;
 const toggleCollapsedGroup = vi.fn();
+const sidebarTaskItemRenderSpy = vi.hoisted(() => vi.fn());
 const taskLocalState = {
   isPinned: vi.fn(() => false),
   isArchived: vi.fn(() => false),
@@ -103,8 +104,9 @@ vi.mock('../../../../src/renderer/components/sidebar/SidebarTaskItem', () => ({
     task: GlobalTask;
     hideProjectName?: boolean;
     teamOffline?: boolean;
-  }) =>
-    React.createElement(
+  }) => {
+    sidebarTaskItemRenderSpy(task.id);
+    return React.createElement(
       'div',
       {
         'data-testid': 'sidebar-task-item',
@@ -112,7 +114,8 @@ vi.mock('../../../../src/renderer/components/sidebar/SidebarTaskItem', () => ({
         'data-team-offline': teamOffline ? 'true' : 'false',
       },
       task.subject
-    ),
+    );
+  },
 }));
 
 vi.mock('../../../../src/renderer/components/sidebar/TaskFiltersPopover', () => ({
@@ -236,6 +239,7 @@ describe('GlobalTaskList project grouping', () => {
     taskLocalState.togglePin.mockClear();
     taskLocalState.toggleArchive.mockClear();
     taskLocalState.renameTask.mockClear();
+    sidebarTaskItemRenderSpy.mockClear();
     setElectronApiForTest(undefined);
     localStorage.clear();
     localStorage.setItem('sidebarTasksGrouping', 'project');
@@ -604,4 +608,57 @@ describe('GlobalTaskList project grouping', () => {
       await flushMicrotasks();
     });
   });
+
+  it('does not rerender unchanged task rows when refreshed task objects keep the same visible fields', async () => {
+    vi.stubGlobal('IS_REACT_ACT_ENVIRONMENT', true);
+    storeState.globalTasks = [makeTask(1), makeTask(2)];
+
+    const host = document.createElement('div');
+    document.body.appendChild(host);
+    const root = createRoot(host);
+
+    await act(async () => {
+      root.render(React.createElement(GlobalTaskList));
+      await flushMicrotasks();
+    });
+
+    expect(sidebarTaskItemRenderSpy).toHaveBeenCalledTimes(2);
+    sidebarTaskItemRenderSpy.mockClear();
+
+    storeState.globalTasks = [makeTask(1), makeTask(2, { subject: 'Task 2 updated' })];
+    await act(async () => {
+      notifyStoreUpdate();
+      await flushMicrotasks();
+    });
+
+    expect(visibleSubjects(host)).toEqual(['Task 1', 'Task 2 updated']);
+    expect(sidebarTaskItemRenderSpy.mock.calls.map(([taskId]) => taskId)).toEqual(['task-2']);
+
+    sidebarTaskItemRenderSpy.mockClear();
+    storeState.globalTasks = [
+      makeTask(1, {
+        comments: [
+          {
+            id: 'comment-1',
+            author: 'alice',
+            text: 'note',
+            createdAt: '2026-04-18T11:00:00.000Z',
+            type: 'regular',
+          },
+        ],
+      }),
+      makeTask(2, { subject: 'Task 2 updated' }),
+    ];
+    await act(async () => {
+      notifyStoreUpdate();
+      await flushMicrotasks();
+    });
+
+    expect(sidebarTaskItemRenderSpy.mock.calls.map(([taskId]) => taskId)).toEqual(['task-1']);
+
+    await act(async () => {
+      root.unmount();
+      await flushMicrotasks();
+    });
+  });
 });